The calculation for lab's science pack consumption rate is incorrect. It doesn't properly include lab research speed bonus from technology. According to the wiki (https://wiki.factorio.com/lab) it is a multiplicative bonus but I think PRCE treats it as an additive bonus. To reproduce that:

1. Create a new world
2. Unlock lab research speed 1 (+20% research speed bonus) and automation science pack through commands
3. Place a lab with two speed modules 3 (+100% speed bonus)
4. Enqueue Automation in research tree

The total research speed is 2.4 (1.2 * 2) so the consumption rate of science packs should be 0.24/s (Automation's research time is 10). However, PRCE shows 0.22/s (I guess it calculates the speed as 1 + 0.2 + 1).

Thanks for the bug report. Should be fixed with sw-rates-lib version 0.4.16

Fixed indeed, thanks!